Multi-field and multi-scale characterization of novel super insulating panels/systems based on silica aerogels: Thermal, hydric, mechanical, acoustic, and fire performance

摘要

The building sector is responsible for a significant part of global energy consumption and greenhouse gas emission. Nowadays, there is a growing interest in the so-called super-insulating materials, particularly Aerogels. The present work examines the performance of novel aerogel blankets obtained thanks to an innovative ambient drying process. Based on these aerogel blankets, two thermal insulation systems are developed: one as external thermal insulation composite system (ETICS) and another one as internal thermal insulation multi-layer system (ITI). The objectives of the current work are to assess the performance of the core material (aerogel blanket) as well as the two developed systems. At a material (core layer) scale, thermal, hydric, and mechanical performance characterizations are carried out. At a system level, in-situ hygrothermal, acoustic, and fire performance characterizations are carried out in real scale test cells.Hygrothermal characterization revealed that the thermal conductivity of the studied blanket is about 0.0165 W/(m.K) in ambient and dry conditions but can increase by up to 40% in a very humid environment (RH 90%). The integration of the aerogel blanket panels into an interior insulating system, tested in a test-cell located in south of France, show great thermal performance. The U value of the wall decreased from 0.63 W/(m(2).K) to 0.33 W/(m(2).K)after retrofitting. The in-situ hygrothermal results showed that the external insulation system protects the wall against the moisture risks. For the internally insulated wall, the relative humidity remains lower than 85% even when high moisture generation is present inside the WA cell. Concerning the thermal performance, the envelope's thermal transmittance is reduced by more than 80% after applying the insulation systems. The ITI system was tested in-situ to airborne sound insulation (facade), reporting significant acoustic improvement in acoustic insulation: +7 dB, equal to a noise reduction to one quarter compared to the base wall without insulation. The fire WA of the ETICS proceeded without any material ignition, while the fire behavior of the internal insulation system depends significantly on the adhesion stability between all single components.